15 Breed-specific Hereditary Diseases and Genetic Screening

Abstract

There is no mammalian species that has a greater phenotypic diversity than the domestic dog (Canis familiaris). This has occurred not because of natural selection, but rather through the domestication of the dog by humans and the associated selection for various uses in different societies. Based on morphological features, such as body size, head and ear form, proportion of body and legs, and coat length and color, the canine species is divided into over 400 distinct breeds (Wilcox and Walkowicz 1995). These breeds also greatly differ with regard to their behavioral traits, such as their suitability for hunting by line of sight or by scent, for retrieving, herding, guarding, and for a number of other specialized roles. Moreover, certain characteristics within a breed may have been further subdivided by geographic separations and selection leading to many additional breeds, which are being recognized by some kennel clubs. Finally, within a breed an individual’s ability to be suitable as a pet or a working dog also varies considerably, thereby reflecting the heterogeneic background of dog breeds. In contrast to many other domesticated species, the evolution and selection of the domestic dog and desired characteristics within a breed were not driven by economic pressures, but rather by humans aiming for suitable companions and working dogs. The selection of a dog as a companion pet by humans depends on many factors and is influenced by dog shows, popularity of a breed, availability, and personal affection.

The domestic dog has become a closely integrated family...